\definefloat
[subfigure]
[subfigures]

\setuplabeltext
[subfigure=]

\setupfloat
[subfigure]
[
location=here,
align={middle},
]
\setcounter[subfigure][0]

\setupcombination[float][
after={\setcounter[subfigure][0]},
]

\setupcaption
[subfigure]
[
number=yes,
location=bottom,
%  prefix=yes,
%   prefixsegments=figure,
numberstarter={\convertnumber{n}{\numexpr\rawcountervalue[figure]+1}-},
%numberstopper={)},
distance=1mm,
numberconversion=a,
style=\rm\tfwuhao,
headstyle=\rm\tfwuhao,
align=middle,
]
